1. Field of the Invention
The present invention relates to an IP (Internet Protocol) packet priority control system on the Internet.
2. Description of the Related Art
Recently, the integration of data and sound is rapidly proceeding on IP networks for Internet terminals.
In the IP networks, image data is frequently handled steadily for browsing Web pages with browsers. The image data is included in an HTTP (Hypertext Transfer Protocol) transaction which is likely to substantially occupy a communication band. Thus, control information vulnerable to delay and sound data requiring real time processing exhibit phenomena such as data delay, fluctuations, data loss and the like on the networks due to the occupation of the communication band by the image data.
For example, these phenomena occur more prominently on wired networks in WAN (Wide Area Network) lines for connecting LANs (Local Area Network) as compared with LAN lines. This is because high cost of the WAN line for connecting LANs per band makes it difficult to ensure a sufficient band. For this reason, it is common practice to put high priority on control information with QoS (Quality of Service) control in a router connected to an exit of the WAN line.
On wireless networks, cellular phones play increasing roles as Internet terminals and image data is handled more frequently. However, a transmission speed based on current techniques has reached the limit to cause the aforementioned phenomena prominently at an exit of a wireless communication path where a sufficient band is difficult to ensure.
The prior art has problems as below.
A first problem is that while the mounting of a CPU of high performance is required in a cellular phone, it is difficult to mount such a CPU of high performance due to desires for a smaller size, lighter weight, and low current consumption of the cellular phone.
A second problem is that priority setting is realized only on an application-by-application basis in existing devices using Diff-serv (Differentiated services). This is because the implementation in one terminal is not considered.